Multiaperture magnetic core



Oct. 6, 1970 J. A. SWANSON MULTIAPERTURE MAGNETIC CORE Original Filed 001:. 15, 1965 2 Sheets-Sheet 1 Oct." 6, 1970 J. A. SWANSON MULTIAPERTURE MAGNETIC CORE Original Filed on. 13, 1965 2 Shets-$heet '2 United States Patent 3,533,092 MULTIAPERTURE MAGNETIC CORE John Arnold Swanson, Harrisburg, Pa., assiguor to AMP Incorporated, Harrisburg, Pa. Continuation of application Ser. No. 495,508, Oct. 13, 1965. This application June 4, 1969, Ser. No. 831,272 Int. Cl. G11c 11/08, /02

U.S. Cl. 340174 2 Claims ABSTRACT OF DISCLOSURE A multiaperture magnetic core having an external periphery of irregular configuration to facilitate handling and orienting of the core and having a large central aperture which generally conforms to the external periphery of the core and having a pair of small apertures of sufficient size to permit a plurality of wires to be fed at right angles to each other straight through the small apertures.

This application is a continuation of application No. 495,508, filed Oct. 13, 1965 which is now abandoned.

This invention relates to the art of magnetic memory devices and more particularly to a new and novel memory plane and a magnetic core for use in such plane.

A memory plane is a device for storing information in a computer or like instrument. The devices are made up of a large number of magnetic cores and an array of wires extending through the apertures in said cores. These cores are normally quite small and quite closely spaced, making the wiring a very difiicult and tedious job. It is known to have a memory plane wherein a plurality of conductive wires extend in two right angled directions and pass through a plurality of cores. In order to permit straight through wiring in the two directions the cores are disposed at a 45 angle, the cores being single apertured cores wherein the aperture through which the wires pass is a relatively large aperture. Examples of this type of memory plane are U.S. Pat. No. 2,934,748 granted to L. E. Steimen and U.S. Pat. No. 2,985,948 granted to C. L. Peters, However, when it is desired to use multiapertured cores rather than single-apertured cores there arises the problem of wiring. Multiapertured cores normally have a central major aperture and a plurality of minor apertures. The minor apertures are of necessity quite small in order to keep the overall core size at a minimum. When several wires are threaded through these small apertures the wires take on a wavy configuration since the apertures are not large enough to permit straight through wiring from more than one direction. This threading of the wires is very time consuming and materially adds to the cost of the memory plane.

It is, therefore, an object of this invention to provide a magnetic core having multiple apertures and permitting straight through wiring in a memory plane.

It is a further object of this invention to provide a memory plane which is of simple and rigid construction and is relatively inexpensive to produce.

A further object is to provide a magnetic core having means to aid in its orientation in a memory plane.

Other objects and attainments of the present invention will became apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purpose of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it ice in various forms, each as may be best suited to the conditions of a particular use.

In the drawings, in which like reference numerals refer to like parts:

FIG. 1 is an exploded perspective view showing a memory plane made in accordance with the teachings of the present invention;

FIG. 2 is a perspective view of a magnetic core for use in the memory plane of FIG. 1;

FIG. 3 is a fragmentary plan view of the memory plane of FIG. 1;

FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. 3; and

FIG. 5 is a cross-sectional view taken along the line 55 of FIG. 3.

In the computing art, information may be retained in magnetic storage devices which may consist of a core made from a magnetic substance which possesses the characteristic of retaining information in a positive or negative magnetic remanent state. Such a core can be used to store signals that can be expressed in binary form, and is driven to its positive remanent state or its negative remanent state. The two stable states indicate a binary one or a binary zero and a read out means may be provided for indicating the particular state of the individual core. For a complete explanation of one such information storage system, reference is made to copending application Ser. No. 244,608, filed Dec. 14, 1962, now Pat. No. 3,298,003, and assigned to the assignee of the instant ap plication. The present invention is concerned with providing an improved core and memory plane configuration for use in a system such as shown. in the above identified copending application and in other similar systems.

FIG. 2 shows the improved core 10 of this invention which is a multiaperture core having a major aperture 12, an input minor aperture 14, and an output minor aperture 16. Aperture 14 divides the core into two legs 18 and 20 while aperture 16 divides the core into two legs 22 and 24. Although numerous possible wiring arrays may be used, the array of the above copending application has been chosen for illustration as one example and comprises an inhibit winding 26 surrounding leg 18, a write winding 28 surrounding legs 18 and 20, a prime winding 30 about leg 22, and a read winding 32 and sense winding 34 about leg 24. Leg 24 is normally a constricted leg and its position on the core must be ascertainable prior to assembly of the core into a memory plane. Because of the size of typical cores it is virtually impossible to visually detect which leg is constricted. It is customary in the prior art to place some marking on the cores to identify the constricted leg. Such a scheme is satisfactory for most purposes but has drawbacks when it is attempted to assemble the cores by automatic machinery. For this purpose the core of the present device is formed with a tapered end around aperture 16 to facilitate the automatic handling and orientation of the core. An important feature of the core rests in the fact that the major aperture 12 follows the periphery of core 10 and the minor apertures 14 and 16 have rounded ends, all providing for smooth flux paths throughout the core.

The memory plane consists generally of a case 36, a frame assembly 38, and a cover 40. The case 36 is a box-like structure and receives the frame assembly 38 which is bonded thereto. The cover 40 fits over the frame assembly and is secured in place by a suitable bonding material. The cover has a series of apertures 42 along three edges to receive the pins of the frame assembly to be described.

The frame assembly 38 will now be described in detail with reference to FIGS. 4 and S. The assembly comprises four frame members 44, 46, '48 and 50, frames 44 and 46 being identical and frames 48 and 50 being identical and differing from frames 44 and 46 only in length. Since the four frame members are alike, only one, frame 50, will be described. The frame 50 has a central section 52 and two end sections 54, section 52 having a plurality of supporting ribs 56 and apertures 58 between said ribs for receiving contact pins 60. A ledge 62 is provided along one side of section 52 for a purpose to be described later. The frames are assembled into a rectangular configuration by inverting two opposite frames, for example 44 and 46, whereby the end sections 54- of the frame members will overlap each other and the end sections are then secured together by a suitable bonding material. A core holder 64 is provided and consists of a thin metallic sheet having a plurality of slots 66 therein, the slots being punched, chemically milled, etc. The slots are arranged in a series of rows 68 and columns 70 with the major dimension of said slots being at an agle of approximately 45 with respect to the edges of holder 64. The core holder is inserted into the assembled frame members and is held in position by the ledges 62, two ledges being above the holder and two below the holder due to the fact that two of the frame members have been inverted as previously explained.

The cores are then placed in the slots 66 with the tapered end portions pointing up, thus orienting all of the cores. The cores are prevented from falling through the slots by a suitable holding fixture (not shown) which is temporarily placed under the core holder.

It is noted that contact pins 60 are placed in frames 46, 4'8 and 50 while frame 44 carries terminal posts 72 in the apertures 58. The posts 72 are arranged in two rows 74 and 76 and are connected by bus lines 7 8 and 80 respectively, bus 78 being a write winding common and bus 80 being a read winding common. A length of insulated magnet wire 82 is secured to each side of the frame assembly by bonding with suitable material for the purpose of aiding in the subsequent wiring of the memory lane.

p The assembly is now ready for wiring and, with the cores positioned as above described, the prime, read and sense windings are threaded through the cores. The assembly is then inverted and the write and inhibit windings are threaded. The write windings are soldered to posts 72 along row 74 and the read windings are secured to posts 72 along row 76. The various windings may be secured to contact pins 70 by soldering or by means of a crimpable cap (not shown) fitting over the pins. The windings are threaded in parallel arrangement in two directions at right angles to each other as shown in the drawings. The threading is straight through the cores so it can be quickly and inexpensively accomplished.

The straight through threading of the various windings is permitted by the unique physical shape of the cores 10. As stated previously the cores are very small for reasons of economy and compactness. While it is desirable to keep core size at a minimum, the minor apertures 14 and 16 of the cores must be large enough to allow several windings to pass therethrough. By elongating the apertures 14 and 16 in a direction transverse to the longitudinal axis of the cores the apertures are enlarged but the overall length of the core is permitted to remain the same. The

relationship between the length of the flux path around the major aperture 12 and around the minor apertures 14 and 16 is one of the circuit parameters which must be held within certain liimts so it is desirable to keep the total path length around the minor apertures of the cores at a minimum, thereby allowing the total path length of the major aperture to be at a minimum. The threading problem arises when the core is miniaturized to the extent that the minor apertures, if circular, have a diameter which is equal to or less than the thickness of the core whereby the minor apertures would not be visible when viewing the core along a line disposed at 45 to the plane of the core. This problem is solved by the present invention by increasing the transverse dimension of the minor apertures to a length greater than the thickness of the core whereby a portion of the aperture is visible along the 45 line to thereby permit straight through wiring.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by Way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

What is claimed is:

1. A magnetic core comprising a body of ferrite material having flat parallel end walls and being generally symmetrical about a central longitudinal axis, said body having a length along said axis which is greater than its width normal to said axis, said body having end sections at each end of said longitudinal axis of dissimilar configuration so as to be readily distinguishable, wherein one of said end sections of said body is tapered inwardly to facilitate handling of said core, a large central aperture in said body having end sections of dissimilar configuration to conform generally to the peripheral shape of said body with end walls parallel to the end walls of the body, and a small aperture in said body disposed at each of opposite ends of said large aperture, said small apertures having end walls parallel to those of the central aperture and having a Width along said axis between the end walls thereof, equal to or less than the thickness of said body, and having a length normal to said axis sufficiently greater than the thickness of said body to permit a portion of the aperture to be visible when viewing the core along a line disposed at 45 to the plane of the core, whereby a plurality of wires can be fed at right angles to each other straight through said small apertures.

2. A magnetic core as set forth in claim 1 wherein the outer wall of said core takes the shape of a continuous function, having no abrupt changes of direction.

References Cited UNITED STATES PATENTS 3,312,959 4/1967 Bennion 340-174 3,214,745 10/1965 Eiseman et al. 340-174 3,271,747 9/1966 Harner et a] 340-174 STANLEY M. URYNOWICZ, JR., Primary Examiner S. B. POKOTILOW, Assistant Examiner 

